Dear All,
This is an RFC.
The first instruction during RAM boot is a branch to _start. This is as desribed in the start.S file for ppc4xx arch. This is not the case when trying to do a RAM boot build for the ppc405 platform.
** Pre-patch build-x405g-pre/u-boot: file format elf32-powerpc Disassembly of section .text: 04000000 <version_string-0x4>: 4000000: 27 05 19 56 dozi r24,r5,6486
** Post-patch build-x405g-post/u-boot: file format elf32-powerpc Disassembly of section .text: 04000000 <version_string-0x8>: 4000000: 48 00 21 01 bl 4002100 <_start> 4000004: 27 05 19 56 dozi r24,r5,6486
Comments are very much welcome.
All the best, Rommel
During RAM boot first instruction at offset 0 of load the load address should be a branch to _start.
Signed-off-by: Rommel G Custodio sessyargc@gmail.com --- arch/powerpc/cpu/ppc4xx/start.S | 5 +++++ boards.cfg | 2 +- 2 files changed, 6 insertions(+), 1 deletion(-)
diff --git a/arch/powerpc/cpu/ppc4xx/start.S b/arch/powerpc/cpu/ppc4xx/start.S index 7aef43b..a2aa02a 100644 --- a/arch/powerpc/cpu/ppc4xx/start.S +++ b/arch/powerpc/cpu/ppc4xx/start.S @@ -267,8 +267,13 @@ * 4xx RAM-booting U-Boot image is started from offset 0 */ .text +#if defined(CONFIG_440) bl _start_440 #endif +#if defined(CONFIG_405) + bl _start +#endif +#endif
/* * 440 Startup -- on reset only the top 4k of the effective diff --git a/boards.cfg b/boards.cfg index 98f7a14..29b73d9 100644 --- a/boards.cfg +++ b/boards.cfg @@ -1086,7 +1086,7 @@ METROBOX powerpc ppc4xx metrobox sandbur xpedite1000 powerpc ppc4xx - xes ml507 powerpc ppc4xx ml507 xilinx - ml507:SYS_TEXT_BASE=0x04000000,RESET_VECTOR_ADDRESS=0x04100000,BOOT_FROM_XMD=1,INIT_TLB=board/xilinx/ppc440-generic/init.o ml507_flash powerpc ppc4xx ml507 xilinx - ml507:SYS_TEXT_BASE=0xF7F60000,RESET_VECTOR_ADDRESS=0xF7FFFFFC,INIT_TLB=board/xilinx/ppc440-generic/init.o -xilinx-ppc405-generic powerpc ppc4xx ppc405-generic xilinx - xilinx-ppc405-generic:SYS_TEXT_BASE=0x04000000,RESET_VECTOR_ADDRESS=0x04100000 +xilinx-ppc405-generic powerpc ppc4xx ppc405-generic xilinx - xilinx-ppc405-generic:SYS_TEXT_BASE=0x04000000,RESET_VECTOR_ADDRESS=0x04100000,BOOT_FROM_XMD=1 xilinx-ppc405-generic_flash powerpc ppc4xx ppc405-generic xilinx - xilinx-ppc405-generic:SYS_TEXT_BASE=0xF7F60000,RESET_VECTOR_ADDRESS=0xF7FFFFFC xilinx-ppc440-generic powerpc ppc4xx ppc440-generic xilinx - xilinx-ppc440-generic:SYS_TEXT_BASE=0x04000000,RESET_VECTOR_ADDRESS=0x04100000,BOOT_FROM_XMD=1 xilinx-ppc440-generic_flash powerpc ppc4xx ppc440-generic xilinx - xilinx-ppc440-generic:SYS_TEXT_BASE=0xF7F60000,RESET_VECTOR_ADDRESS=0xF7FFFFFC